Anti-Candida activity of Tripodanthus acutifolius (Loranthaceae), mechanism of action and toxicity parameters

Abstract

The extensive use of azoles antifungals against infections caused by Candida species has been contributing to the selection of resistant strains to this antifungal class, demonstrating that the prospection of new antifungal agents is essential and urgent. Tripodanthus acutifolius (Loranthaceae) is a plant widely used in folk medicine with reported antimicrobial activity. In this context, this study aimed to evaluate the antifungal potential and the mechanisms of action of the crude methanolic extract (CME) of T. acutifolius leaves against Candida species, as well as evaluate their toxicity parameters. As results, the phytochemical characterization of CME suggested the presence of four phenolic compounds as well as a tripodantoside compound. The CME presented minimum inhibitory concentration (MIC) between 16 to 64 μg mL-1, with antifungal action possibly occurring in the fungal cell wall. In addition, the CME showed a synergic effect in combination with fluconazole (FLC). The CME demonstrated no mucosal irritation or tissue damage at all tested concentrations, as well as no cytotoxicity at the MIC values. This study is unprecedented and suggests that T. acutifolius is a new promising source for the development of anti-Candida agents on its own or as chemosensitizer associated to FLC.The extensive use of azoles antifungals against infections caused by Candida species has been contributing to the selection of resistant strains to this antifungal class, demonstrating that the prospection of new antifungal agents is essential and urgent. Tripodanthus acutifolius (Loranthaceae) is a plant widely used in folk medicine with reported antimicrobial activity. In this context, this study aimed to evaluate the antifungal potential and the mechanisms of action of the crude methanolic extract (CME) of T. acutifolius leaves against Candida species, as well as evaluate their toxicity parameters. As results, the phytochemical characterization of CME suggested the presence of four phenolic compounds as well as a tripodantoside compound. The CME presented minimum inhibitory concentration (MIC) between 16 to 64 μg mL-1, with antifungal action possibly occurring in the fungal cell wall. In addition, the CME showed a synergic effect in combination with fluconazole (FLC). The CME demonstrated no mucosal irritation or tissue damage at all tested concentrations, as well as no cytotoxicity at the MIC values. This study is unprecedented and suggests that T. acutifolius is a new promising source for the development of anti-Candida agents on its own or as chemosensitizer associated to FLC.